Ghattu's Technology Blog » Clustering http://ghattus.com A blog about technology that I work on in my day to day job Thu, 03 Dec 2009 00:56:54 +0000 en hourly 1 http://wordpress.org/?v=3.3.1 WebLogic Clustering with Unicast http://ghattus.com/2009/06/04/weblogic-clustering-with-unicast/ http://ghattus.com/2009/06/04/weblogic-clustering-with-unicast/#comments Fri, 05 Jun 2009 01:49:00 +0000 sghattu http://ghattus.com/2009/06/weblogic-clustering-with-unicast/ Until WebLogic 9.2 the only communication mode available between the Cluster members of your WebLogic domain is ‘Multicast’. Starting with WebLogic 10.0, Oracle in addition to MultiCast, supports communication between the Cluster members using Unicast. Quick definitions of Unicast and Multicast from Wikipedia.

Unicast:

Unicast messaging is used for all network processes where a private or unique resource is requested making most networking traffic Unicast in form. Unicast is used where two way connections are needed to complete the network transaction.

Multicast:

Multicast addressing is a network technology for the delivery of information to a group of destinations simultaneously using the most efficient strategy to deliver the messages over each link of the network only once, creating copies only when the links to the multiple destinations split.

I believe, support for Unicast is a very important feature. Although Multicast is efficient when compared to Unicast, it causes a network configuration overhead where your Network Administrator need to dedicate a Multicast address. Also, when using Multicast you should make sure the end points or systems that don’t want the information have to be shielded from receiving these unwanted multicast broadcast messages.

Recently we have automated our Cluster configuration creations to Unicast messaging mode. In this post I would like to share wlst scripts and some guidelines to follow when using Unicast. Assuming you already have a domain, let us create a Cluster definition. First connect to the server and start an edit session

connect(uname,pwd,url)

edit()

startEdit()


 
 

 

 

 

Now create the Cluster and set the messaging mode to ‘unicast’.

 

theCluster = cmo.createCluster(‘mycluster’)

 

theCluster.setClusterMessagingMode(‘unicast’);

 

It is recommended to use a custom broadcast channel instead of the default.

 

theCluster.setClusterBroadcastChannel(‘myclusterChannel’);

 

 

 

Now let’s create a basic managed server and add that to the cluster. We will configure a Network access point for the managed server that will be used for communicating with other managed servers in the cluster.

 

msSvr = cmo.createServer(“ms1”)

msSvr.setListenAddress(“msMachine”)

msSvr.setListenPort(8001)

msSvr.setCluster(theCluster)

cd(‘/Servers/ms’)

cmo.createNetworkAccessPoint(‘myclusterChannel’) 

cd(‘/Servers/ms/NetworkAccessPoints/myclusterChannel’)

cmo.setListenPort(8002)

cmo.setPublicPort(-1)

cmo.setEnabled(true)

 if you would like to secure conmmunication between the servers

 

cmo.setProtocol(‘cluster-broadcast-secure’)

  

Now make sure you enable the Outbound communication for this channel, otherwise your managed server will not be able to communicate with other managed servers in the cluster. 

cmo.setOutboundEnabled(true)

 

I have pasted the entire working script below that you can use to create a 2 Node Cluster that uses Unicast messaging mode on a custom Network channel.

def init():
connect(uname,pwd,url)
edit()
startEdit()

def createCluster(clusterName):
theCluster = cmo.createCluster(clusterName)
theCluster.

setClusterMessagingMode(‘unicast’);
# It is recommended to use a custom broadcast channel instead of default
theCluster.setClusterBroadcastChannel(‘myclusterChannel’);
return theCluster

def createMS(msname, port, mname, channelPort, clusterBean):
msSvr1 = cmo.createServer(msname)
msSvr1.setListenAddress(mname)
msSvr1.setListenPort(port)
msSvr1.setCluster(clusterBean)
cd(‘/Servers/’+msname)
cmo.createNetworkAccessPoint(‘myclusterChannel’)
cd(‘/Servers/’+msname+’/NetworkAccessPoints/myclusterChannel’)
# if you want secure conmmunication between the servers
cmo.setProtocol(‘cluster-broadcast-secure’)
cmo.setListenPort(channelPort)
cmo.setPublicPort(-1)
cmo.setEnabled(true)
# This is very very important
cmo.setOutboundEnabled(true)
cd(‘/’)

def run():
init()
bean = createCluster(‘mycluster’)
createMS(“ms1″,8001,”ms1Machine”,8002,bean)
save()
activate()

run()

]]> http://ghattus.com/2009/06/04/weblogic-clustering-with-unicast/feed/ 8